Network monitoring plays a crucial role in any network management environment. Especially nowadays, with network speed and load constantly increasing, more and more data needs to be collected and efficiently processed. In highly interactive network monitoring systems, a quick response time from information sources turns out to be a crucial requirement. However, for data sets in the order of several GBs, this goal becomes difficult to achieve. In this paper, we present our operational experience in dealing with large amounts of network data. In particular, we focus on MySQL and NfDump, testing their capabilities under different usage scenarios and increasing data set sizes.